Wide-flanged concrete girders are increasingly being used for highway bridges in Wisconsin. The objective of this research was to understand the state of the art of non-metallic SIP forms and to develop design guidelines and performance specifications that can be used locally for the construction of highway bridge decks. Four major types of stay-in-place (SIP) forms using fiber reinforced concrete (FRC) or fiber reinforced polymer (FRP) materials were investigated: fiber reinforcements, grid reinforcements, bar reinforcements and pultruded profiles. The results were used to develop a model design and construction specification for non-structural, non-metallic, SIP forms in highway bridge decks.

At head of title: National Cooperative Highway Research Program.

This report documents and presents results of a study to determine time-dependent behavior and relevant design criteria for simple-span precast, prestressed bridge girders made continuous. A questionnaire was used to determine current practice. Creep and shrinkage tests of steam-cured concrete loaded at an early age were made. Computer simulations were used to investigate the effects of time-dependent material behavior and variation in design parameters on the effective continuity for live load plus impact. The findings suggest that positive moment connections in the diaphragms at the piers are not required and provide no structural advantages. The findings also suggest that effective continuity for live load plus impact can vary from 0 to 100% dependent on the design parameters and timing of construction. Computer analyses were also used to determine an upper limit for the amount of negative moment reinforcement over the supports to insure full moment redistribution and attainment of maximum bridge strength. New computer programs were developed for simplified analysis to determine time-dependent effects and service moments. Recommendations for design procedures were presented and design examples given.

This report establishes a user's manual for the acceptance, repair, or rejection of precast/prestressed concrete girders with longitudinal web cracking. The report also proposes revisions to the AASHTO LRFD Bridge Design Specifications and provides recommendations to develop improved crack control reinforcement details for use in new girders. The material in this report will be of immediate interest to bridge engineers.

Introduction and Research Approach -- Findings -- Interpretation, Appraisal, and Application -- Interpretation, Appraisal, and Application -- References -- Appendixes.